They have a catty past, with names like "Barbie" and "saggy teabag" being used, but they seemed to have moved on once in the house together.

Then the argument happened.

Loud-mouthed TV personality Katie Hopkins laid into Katie Price over her son Harvey's treatment, because the former glamour model can afford to pay for it.

Katie's 12 year old son Harvey is blind, autistic , and has a condition called septo-optic dysplasia.

She'd had a conversation in the house with Nadia Sawahla, and said her son’s driver who drives Harvey to school is funded by the government and he also has a nurse that sits in the car with him on the journeys.

Katie Hopkins immediately challenged Price, who is worth an estimated £40 million, on why she wouldn’t pay for that treatment herself.

“Do you know how f***ing expensive that would be… it would be up to a grand a day,” the mother-of-five retaliated.

But it's not the first. Here are some of their biggest arguments:

Katie Price defends Lily Allen and mums around the world

(Image: Rex/Getty)

Who could forget Katie Hopkins' cruel fat jibes at half the population?

Well, Katie Price didn't like them one bit - and when the controversial former Apprentice star made a stab at Lily Allen, enough was enough.

The former model jumped to the singer's defence - branding Hopkins a SAGGY TEABAG.

Writing in her Now magazine column, Pricey wrote: "In her usual tongue-in-cheek, but obvious veiled attack, [Hopkins] commented that Lily had 'removed herself from the spotlight because she wanted to be a mother and that largely involved gaining 2st and looking pretty hideous'."

"I think it’s brilliant that Lily’s able to take a career break, introduce two lovely children to the world and then return to singing – something she enjoys and is exceptionally good at… and she looks pretty darn good if you ask me."

But not content with that, she then added: "I could easily comment on Katie’s appearance as I pull out a saggy tea bag from my mug. But she’d love the attention."

Hopkins brands Pricey a "Barbie"

Katie hasn't exactly kept her feelings towards Pricey to herself in the past, and branded the former glamour model a "Barbie" during a 2014 saints and sinners round-up for Now magazine in December.

After laying into Kelly Brook, Ms Hopkins turned to Katie, and put her on the sinners list too, saying: "I don't know where she's going to go - I can become more and more of a grumpy old woman and morph into Victor Meldrew, but her thing is looking like Barbie.

"Where's Barbie going to go when she gets old? She can be Haggard Barbie for Christmas."

Katie Hopkins calls her rival a "wreck of a woman"

Telly star Katie decided to lay into The Pricey over her choice of outfit earlier that week. The mum-of-five wore a latex catsuit with a giant pair of lips on the front to promote her new perfume.

The angry weight loss guru wrote in her Sun column: "What a wreck of a woman.

"Dressed in a black neoprene catsuit, it looks as though her face might melt near an open fire.

"I feel sorry for the daft trout. Get that catsuit off and give yourself a good hose down with disinfectant.

"And if you buy Kissable Fierce, remember that's not what you become. It makes you Sweaty Has-been."

NOT Bunny!

While they've now become used to hating each other, none of that came close to the moment she poked fun at Katie's choice of baby name back in September.

After finding out that Katie had named her bundle of joy Bunny, Hopkins - who has a real problem with certain children's names - decided to try and cause as much upset as possible by launching a cruel rant on Twitter.

"Bunny? BUNNY?! Makes sense I guess, given your dad was going at it like a rabbit with all of mums mates," she tweeted.

Poor Pricey was left distraught last year after she found out her hubby Kieran Hayler had been cheating on her with two of her pals - so we can't imagine she appreciated Hopkins' cruel comments.